The Novel Cardiac Myosin Activator Danicamtiv Improves Cardiac Systolic Function at the Expense of Diastolic Dysfunction In Vitro and In Vivo: Implications for Clinical Applications.

Recent cardiotropic drug developments have focused on cardiac myofilaments. Danicamtiv, the second direct myosin activator, has achieved encouraging results in preclinical and clinical studies, thus implicating its potential applicability in the treatment of heart failure with reduced ejection fraction (HFrEF). Here, we analyzed the inotropic effects of danicamtiv in detail. To this end, changes in sarcomere length and intracellular Ca2+ levels were monitored in parallel, in enzymatically isolated canine cardiomyocytes, and detailed echocardiographic examinations were performed in anesthetized rats in the absence or presence of danicamtiv. The systolic and diastolic sarcomere lengths decreased; contraction and relaxation kinetics slowed down with increasing danicamtiv concentrations without changes in intracellular Ca2+ transients in vitro. Danicamtiv evoked remarkable increases in left ventricular ejection fraction and fractional shortening, also reflected by changes in systolic strain. Nevertheless, the systolic ejection time was significantly prolonged, the ratio of diastolic to systolic duration was reduced, and signs of diastolic dysfunction were also observed upon danicamtiv treatment in vivo. Taken together, danicamtiv improves cardiac systolic function, but it can also limit diastolic performance, especially at high drug concentrations.

Repetitive levosimendan treatment in the management of advanced heart failure.

Inotropes may be an appropriate treatment for patients with advanced heart failure (AdHF) who remain highly symptomatic despite optimized standard therapies. Objectives for inotrope use in these situations include relief of symptoms and improvement of quality of life, and reduction in unplanned hospitalizations and the costs associated with such episodes. All of these goals must be attained without compromising survival. Encouraging findings with intermittent cycles of intravenous levosimendan have emerged from a range of exploratory studies and from three larger controlled trials (LevoRep, LION-HEART, and LAICA) which offered some evidence of clinical advantage. In these settings, however, obtaining statistically robust data may prove elusive due to the difficulties of endpoint assessment in a complex medical condition with varying presentation and trajectory. Adoption of a composite clinical endpoint evaluated in a hierarchical manner may offer a workable solution to this problem. Such an instrument can explore the proposition that repetitive administration of levosimendan early in the period after discharge from an acute episode of worsening heart failure may be associated with greater subsequent clinical stability vis-à-vis standard therapy. The use of this methodology to develop a 'stability score' for each patient means that all participants in such a trial contribute to the overall outcome analysis through one or more of the hierarchical endpoints; this has helpful practical implications for the number of patients needed and the length of follow-up required to generate endpoint data. The LeoDOR study (NCT03437226), outlined in this review, has been designed to explore this new approach to outcome assessment in AdHF.

[Hungarian Heart Failure Registry 2015-2016. Preliminary results]. / Magyar Szívelégtelenség Regiszter 2015­2016. Kezdeti eredmények.

Heart failure is associated with a poor prognosis despite significant advances in the pharmacological and device therapy and incurs very high cost because of frequent hospitalizations. Therefore, professional high-quality care is essential for both patients and the healthcare system. The best way to evaluate the quality of care for a particular disease is the use of disease-specific registries. Until now, there has not been a registry evaluating characteristics and management of heart failure patients in Hungary. For that reason, the Hungarian Society of Cardiology initiated the set-up of the Hungarian Heart Failure Registry. The Aim of this paper is to present the goals, methods and first year results of the Hungarian Heart Failure Registry. The goal of the Registry is to create a modern, web-based database that summarizes the data of large number of patients who are currently or were previously admitted to hospital or who are currently or were previously patients in an outpatient department due to severe heart failure (NYHA III-IV). Currently 17 cardiology departments participate in the development of the Registry. The planned number of patients is 2000. Initially follow-up was planned for one year (pilot study). After the evaluation of the relevant experiences of the pilot study, long-term follow-up is planned. The Registry collects information about the type of heart failure (heart failure with reduced - LVEF≤45% - vs. preserved - LVEF>45% - ejection fraction), etiology, co-morbidities, diagnostic methods, treatment as well as morbidity and mortality. After the first year, assessing the baseline parameters of 698 patients enrolled in the Registry we found that the majority of patients (87.8%) has heart failure with reduced ejection fraction and in 39.8% of the patients heart failure has an ischaemic origin. The most frequent co-morbidity was hypertension followed by diabetes, renal insufficiency and COPD. The patients were treated with ACE inhibitors or ARBs in 94.4%, with beta blockers in 95.9%, and mineralocorticoid receptor antagonists in 73.9%. The mean dose of neurohormonal antagonists was higher than half of the target dose defined by current guidelines. The use of cardiac resynchronisation therapy was 11.7% and implantable cardioverter defibrillator was 25.8%. The pharmacological and device therapy of patients who were enrolled in the Registry until now was fit the current guidelines' recommendations. This, however, does not mean that the management of heart failure is without problems in our country but that high quality patient care is available with adequate heart failure treatment in cardiology departments dedicated to heart failure care. Orv. Hetil., 2017, 158(3), 94-100.

Sex-specific chronic stress response at the level of adrenal gland modified sexual hormone and leptin receptors.

AIM: To compare cardiometabolic risk-related biochemical markers and sexual hormone and leptin receptors in the adrenal gland of rat males, non-ovariectomized females (NON-OVX), and ovariectomized females (OVX) under chronic stress. METHODS: Forty six 16-week-old Sprague-Dawley rats were divided into male, NON-OVX, and OVX group and exposed to chronic stress or kept as controls. Weight, glucose tolerance test (GTT), serum concentration of glucose, and cholesterol were measured. Adrenal glands were collected at the age of 28 weeks and immunohistochemical staining against estrogen beta (ERß), progesterone (PR), testosterone (AR), and leptin (Ob-R) receptors was performed. RESULTS: Body weight, GTT, serum cholesterol, and glucose changed in response to stress as expected and validated the applied stress protocol. Stressed males had significantly higher number of ERß receptors in comparison to control group (P = 0.028). Stressed NON-OVX group had significantly decreased AR in comparison to control group (P = 0.007). The levels of PR did not change in any consistent pattern. The levels of Ob-R increased upon stress in all groups, but the significant difference was reached only in the case of stressed OVX group compared to control (P = 0.033). CONCLUSION: Chronic stress response was sex specific. OVX females had similar biochemical parameters as males. Changes upon chronic stress in adrenal gland were related to an increase in testosterone receptor in females and decrease in estrogen receptor in males.

Single acute stress-induced progesterone and ovariectomy alter cardiomyocyte contractile function in female rats.

AIM: To assess how ovarian-derived sex hormones (in particular progesterone) modify the effects of single acute stress on the mechanical and biochemical properties of left ventricular cardiomyocytes in the rat. METHODS: Non-ovariectomized (control, n=8) and ovariectomized (OVX, n=8) female rats were kept under normal conditions or were exposed to stress (control-S, n=8 and OVX-S, n=8). Serum progesterone levels were measured using a chemiluminescent immunoassay. Left ventricular myocardial samples were used for isometric force measurements and protein analysis. Ca(2+)-dependent active force (Factive), Ca(2+)-independent passive force (Fpassive), and Ca(2+)-sensitivity of force production were determined in single, mechanically isolated, permeabilized cardiomyocytes. Stress- and ovariectomy-induced alterations in myofilament proteins (myosin-binding protein C [MyBP-C], troponin I [TnI], and titin) were analyzed by sodium dodecyl sulfate gel electrophoresis using protein and phosphoprotein stainings. RESULTS: Serum progesterone levels were significantly increased in stressed rats (control-S, 35.6±4.8 ng/mL and OVX-S, 21.9±4.0 ng/mL) compared to control (10±2.9 ng/mL) and OVX (2.8±0.5 ng/mL) groups. Factive was higher in the OVX groups (OVX, 25.9±3.4 kN/m(2) and OVX-S, 26.3±3.0 kN/m(2)) than in control groups (control, 16.4±1.2 kN/m(2) and control-S, 14.4±0.9 kN/m(2)). Regarding the potential molecular mechanisms, Factive correlated with MyBP-C phosphorylation, while myofilament Ca(2+)-sensitivity inversely correlated with serum progesterone levels when the mean values were plotted for all animal groups. Fpassive was unaffected by any treatment. CONCLUSION: Stress increases ovary-independent synthesis and release of progesterone, which may regulate Ca(2+)-sensitivity of force production in left ventricular cardiomyocytes. Stress and female hormones differently alter Ca(2+)-dependent cardiomyocyte contractile force production, which may have pathophysiological importance during stress conditions affecting postmenopausal women.

Add-on Sacubitril/Valsartan Therapy Induces Left Ventricular Remodeling in Non-responders to Cardiac Resynchronization Therapy to a Similar Extent as in Heart Failure Patients Without Resynchronization.

INTRODUCTION: Non-responders to cardiac resynchronization therapy (CRT-NR) have poor prognosis. Sacubitril/valsartan (SV) treatment improved the outcome of patients with heart failure with reduced left ventricular (LV) ejection fraction (HFrEF) in randomized trials with no data on the specific cohort of CRT-NRs. The aim of this study was to compare the echocardiographic and biomarker changes in CRT-NR patients treated with versus without SV, and in patients with HFrEF on SV therapy. METHODS: CRT-NR patients initiated on SV (group I), CRT-NR patients on angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARB) (group II), and patients with HFrEF (without CRT) initiated on SV (group III) were identified in our heart failure (HF) registry. CRT-NR was defined as < 10% improvement in left ventricular ejection fraction (LV EF) 6 months after the implantation. Echocardiographic parameters and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels at baseline and at the end of follow-up were compared. RESULTS: A total of 275 patients (group I, 70; group II, 70; and group III, 135) were included. After a follow-up of 7.54 ± 1.8 months (mean ± standard deviation [SD]), LV EF (%) increased in group I (25.2 ± 5.7 versus 29.4% ± 6.7; p < 0.001) and in group III (26.6 ± 6.4 versus 29.9 ± 6.7; p < 0.001). LV end-systolic diameters (mm) decreased in group I (56.6 ± 9.0 versus 54.3 ± 8.7; p = 0.004) and in group III (55.9 ± 9.9 versus 54.3 ± 11.2; p = 0.021). The levels of NT-proBNP (pg/mL) decreased in group I (2058.86 [1041.07-4502.51] versus 1121.55 [545-2541]; p < 0.001) and in group III (2223.35 [1233.03-4795.96] versus 1123.09 [500.38-2651.27]; p < 0.001). The extent of improvement was similar in groups I and III (p > 0.05). No significant changes were detected in group II. CONCLUSION: SV therapy induced similar improvements in echocardiographic parameters and in NT-proBNP levels in CRT-NR patients and in patients with HFrEF without resynchronization.

Distinct subsets of anti-pulmonary autoantibodies correlate with disease severity and survival in severe COVID-19 patients.

Autoantibodies targeting the lung tissue were identified in severe COVID-19 patients in this retrospective study. Fifty-three percent of 104 patients developed anti-pulmonary antibodies, the majority of which were IgM class, suggesting that they developed upon infection with SARS-CoV-2. Anti-pulmonary antibodies correlated with worse pulmonary function and a higher risk of multiorgan failure that was further aggravated if 3 or more autoantibody clones were simultaneously present (multi-producers). Multi-producer patients were older than the patients with less or no autoantibodies. One of the identified autoantibodies (targeting a pulmonary protein of ~ 50 kDa) associated with worse clinical outcomes, including mortality. In summary, severe COVID-19 is associated with the development of lung-specific autoantibodies, which may worsen the clinical outcome. Tissue proteome-wide tests, such as the ones applied here, can be used to detect autoimmunity in the post-COVID state to identify the cause of symptoms and to reveal a new target for treatment.

Incidence and predictors of heart failure with improved ejection fraction category in a HFrEF patient population.

AIMS: The aim of the study was to assess the incidence and predictive factors of the development of heart failure with improved ejection fraction (HFimpEF) category during a 1 year follow-up period in a heart failure with reduced ejection fraction (HFrEF) patient population managed in a heart failure outpatient clinic. METHODS AND RESULTS: The study evaluated data from patients enrolled in the Hungarian Heart Failure Registry (HHFR). The incidence and predictive factors of the development of the HFimpEF category after 1 year follow-up were assessed in the group of patients who had HFrEF at baseline. We evaluated the incidence and predictors of the development of HFimpEF after a 1 year follow-up in relation to time since diagnosis of HFrEF in patients diagnosed within 3 months, between 3 months and 1 year, and beyond 1 year. The predictive factors of the development of HFimpEF were analysed using univariate and multivariate logistic regression analysis. Of the 833 HFrEF patients enrolled in the HHFR, the development of HFimpEF was observed in 162 patients (19.5%) during 1 year follow-up. In the whole patient population, independent predictors of the development of HFimpEF were female gender [odds ratio (OR): 1.73; 95% confidence interval (CI): 1.01-2.96; P < 0.05], non-ischaemic aetiology (OR: 1.95; 95% CI: 1.15-3.30; P < 0.05), and left ventricular end-diastolic diameter (LVEDD) <60 mm (OR: 2.04; 95% CI: 1.18-3.51; P < 0.05). The 1 year incidence of HFimpEF decreased in relation to time since diagnosis of HFrEF. The incidence of HFimpEF was 27.1% in patients diagnosed within 3 months, 18.4% in patients diagnosed between 3 months and 1 year, and 12.2% in patients diagnosed beyond 1 year. Non-ischaemic aetiology (OR: 4.76; 95% CI: 1.83-12.4; P < 0.01) and QRS width (OR: 0.81; 95% CI: 0.71-0.94; P < 0.01) for patients diagnosed within 3 months, LVEDD (OR: 0.54; 95% CI: 0.32-0.90; P < 0.05) and left atrial diameter ≤45 mm (OR: 5.44; 95% CI: 1.45-20.4; P < 0.05) for patients diagnosed between 3 months and 1 year, and LVEDD < 67 mm (OR: 2.71; 95% CI: 1.07-6.88; P < 0.05) for patients diagnosed beyond 1 year were found to be independent predictive factors. CONCLUSIONS: In our study, in this HFrEF patient population managed in a heart failure outpatient clinic, the 1 year incidence of HFimpEF was found to be ~20%. The 1 year incidence of HFimpEF decreased in relation to time since diagnosis of HFrEF. The most important predictors of the development of HFimpEF were female sex, non-ischaemic aetiology, narrower QRS width, and smaller diameter of the left ventricle and left atrium.

Protocolized Natriuresis-Guided Decongestion Improves Diuretic Response: The Multicenter ENACT-HF Study.

BACKGROUND: The use of urinary sodium to guide diuretics in acute heart failure is recommended by experts and the most recent European Society of Cardiology guidelines. However, there are limited data to support this recommendation. The ENACT-HF study (Efficacy of a Standardized Diuretic Protocol in Acute Heart Failure) investigated the feasibility and efficacy of a standardized natriuresis-guided diuretic protocol in patients with acute heart failure and signs of volume overload. METHODS: ENACT-HF was an international, multicenter, open-label, pragmatic, 2-phase study, comparing the current standard of care of each center with a standardized diuretic protocol, including urinary sodium to guide therapy. The primary end point was natriuresis after 1 day. Secondary end points included cumulative natriuresis and diuresis after 2 days of treatment, length of stay, and in-hospital mortality. All end points were adjusted for baseline differences between both treatment arms. RESULTS: Four hundred one patients from 29 centers in 18 countries worldwide were included in the study. The natriuresis after 1 day was significantly higher in the protocol arm compared with the standard of care arm (282 versus 174 mmol; adjusted mean ratio, 1.64; P<0.001). After 2 days, the natriuresis remained higher in the protocol arm (538 versus 365 mmol; adjusted mean ratio, 1.52; P<0.001), with a significantly higher diuresis (5776 versus 4381 mL; adjusted mean ratio, 1.33; P<0.001). The protocol arm had a shorter length of stay (5.8 versus 7.0 days; adjusted mean ratio, 0.87; P=0.036). In-hospital mortality was low and did not significantly differ between the 2 arms (1.4% versus 2.0%; P=0.852). CONCLUSIONS: A standardized natriuresis-guided diuretic protocol to guide decongestion in acute heart failure was feasible, safe, and resulted in higher natriuresis and diuresis, as well as a shorter length of stay.

Omecamtiv mecarbil augments cardiomyocyte contractile activity both at resting and systolic Ca2+ levels.

AIMS: Heart failure with reduced ejection fraction (HFrEF) is a disease with high mortality and morbidity. Recent positive inotropic drug developments focused on cardiac myofilaments, that is, direct activators of the myosin molecule and Ca2+ sensitizers for patients with advanced HFrEF. Omecamtiv mecarbil (OM) is the first direct myosin activator with promising results in clinical studies. Here, we aimed to elucidate the cellular mechanisms of the positive inotropic effect of OM in a comparative in vitro investigation where Ca2+ -sensitizing positive inotropic agents with distinct mechanisms of action [EMD 53998 (EMD), which also docks on the myosin molecule, and levosimendan (Levo), which binds to troponin C] were included. METHODS: Enzymatically isolated canine cardiomyocytes with intact cell membranes were loaded with Fura-2AM, a Ca2+ -sensitive, ratiometric, fluorescent dye. Changes in sarcomere length (SL) and intracellular Ca2+ concentration were recorded in parallel at room temperature, whereas cardiomyocyte contractions were evoked by field stimulation at 0.1 Hz in the presence of different OM, EMD, or Levo concentrations. RESULTS: SL was reduced by about 23% or 9% in the presence of 1 µM OM or 1 µM EMD in the absence of electrical stimulation, whereas 1 µM Levo had no effect on resting SL. Fractional sarcomere shortening was increased by 1 µM EMD or 1 µM Levo to about 152%, but only to about 128% in the presence of 0.03 µM OM. At higher OM concentrations, no significant increase in fractional sarcomere shortening could be recorded. Contraction durations largely increased, whereas the kinetics of contractions and relaxations decreased with increasing OM concentrations. One-micromole EMD or 1 µM Levo had no effects on contraction durations. One-micromole Levo, but not 1 µM EMD, accelerated the kinetics of cardiomyocyte contractions and relaxations. Ca2+ transient amplitudes were unaffected by all treatments. CONCLUSIONS: Our data revealed major distinctions between the cellular effects of myofilament targeted agents (OM, EMD, or Levo) depending on their target proteins and binding sites, although they were compatible with the involvement of Ca2+ -sensitizing mechanisms for all three drugs. Significant part of the cardiotonic effect of OM relates to the prolongation of systolic contraction in combination with its Ca2+ -sensitizing effect.

Diabetes mellitus worsens diastolic left ventricular dysfunction in aortic stenosis through altered myocardial structure and cardiomyocyte stiffness.

BACKGROUND: Aortic stenosis (AS) and diabetes mellitus (DM) are frequent comorbidities in aging populations. In heart failure, DM worsens diastolic left ventricular (LV) dysfunction, thereby adversely affecting symptoms and prognosis. Effects of DM on diastolic LV function were therefore assessed in aortic stenosis, and underlying myocardial mechanisms were identified. METHODS AND RESULTS: Patients referred for aortic valve replacement were subdivided into patients with AS and no DM (AS; n=46) and patients with AS and DM (AS-DM; n=16). Preoperative Doppler echocardiography and hemodynamics were implemented with perioperative LV biopsies. Histomorphometry and immunohistochemistry quantified myocardial collagen volume fraction and myocardial advanced glycation end product deposition. Isolated cardiomyocytes were stretched to 2.2-µm sarcomere length to measure resting tension (F(passive)). Expression and phosphorylation of titin isoforms were analyzed with gel electrophoresis with ProQ Diamond and SYPRO Ruby stains. Reduced LV end-diastolic distensibility in AS-DM was evident from higher LV end-diastolic pressure (21±1 mm Hg for AS versus 28±4 mm Hg for AS-DM; P=0.04) at comparable LV end-diastolic volume index and attributed to higher myocardial collagen volume fraction (AS, 12.9±1.1% versus AS-DM, 18.2±2.6%; P<0.001), more advanced glycation end product deposition in arterioles, venules, and capillaries (AS, 14.4±2.1 score per 1 mm(2) versus AS-DM, 31.4±6.1 score per 1 mm2; P=0.03), and higher F(passive) (AS, 3.5±1.7 kN/m2 versus AS-DM, 5.1±0.7 kN/m2; P=0.04). Significant hypophosphorylation of the stiff N2B titin isoform in AS-DM explained the higher F(passive) and normalization of F(passive) after in vitro treatment with protein kinase A. CONCLUSIONS: Worse diastolic LV dysfunction in AS-DM predisposes to heart failure and results from more myocardial fibrosis, more intramyocardial vascular advanced glycation end product deposition, and higher cardiomyocyte F(passive), which was related to hypophosphorylation of the N2B titin isoform.

[Heart failure with preserved ejection fraction (diastolic heart failure)]. / Szívelégtelenség megorzött ejekciós frakcióval (diasztolés szívelégtelenség).

Diastolic heart failure, which is also called as heart failure with preserved ejection fraction, is a clinical syndrome in which patients have signs and symptoms of heart failure, normal or near normal left ventricular ejection fraction (≥ 50%) and evidence of diastolic dysfunction. Recent epidemiological studies have demonstrated that more than half of all heart failure patients have diastolic heart failure. The syndrome is more common in women than in men and the prevalence increases with age. Patients with diastolic heart failure form a fairly heterogeneous group with complex pathophysiologic mechanisms. The disease is often in association with other comorbidities, such as hypertension, diabetes mellitus or obesity. The diagnosis of diastolic heart failure is best achieved by two-dimensional and Doppler echocardiography, which can detect abnormal myocardial relaxation, decreased compliance and increased filling pressure in the setting of normal left ventricular dimensions and preserved ejection fraction. Unlike heart failure with reduced ejection fraction, there is no such an evidence-based treatment for heart failure with preserved ejection fraction, which would improve clinical outcomes. Thus, pharmacological therapy of diastolic heart failure is based mainly on empiric data, and aims to the normalization of blood pressure, reduction of left ventricular dimensions and increased heart rate, maintenance of normal atrial contraction and treatment of symptoms caused by congestion. Beneficial effects of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers may be utilized in patients with diastolic dysfunction, especially in those with hypertension. Beta-blockers appear to be useful in lowering heart rate and thereby prolonging left ventricular diastolic filling time, while diuretic therapy is the mainstay of treatment for preventing pulmonary congestion. Nonetheless, treatment of the underlying disease is also an important therapeutic approach. This review summarizes the state of current knowledge with regard to diastolic heart failure.

The Genetic Architecture of Hypertrophic Cardiomyopathy in Hungary: Analysis of 242 Patients with a Panel of 98 Genes.

Hypertrophic cardiomyopathy (HCM) is a primary disease of the myocardium most commonly caused by mutations in sarcomeric genes. We aimed to perform a nationwide large-scale genetic analysis of a previously unreported, representative HCM cohort in Hungary. A total of 242 consecutive HCM index patients (127 men, 44 ± 11 years) were studied with next generation sequencing using a custom-designed gene-panel comprising 98 cardiomyopathy-related genes. A total of 90 patients (37%) carried pathogenic/likely pathogenic (P/LP) variants. The percentage of patients with P/LP variants in genes with definitive evidence for HCM association was 93%. Most of the patients with P/LP variants had mutations in MYBPC3 (55 pts, 61%) and in MYH7 (21 pts, 23%). Double P/LP variants were present in four patients (1.7%). P/LP variants in other genes could be detected in ≤3% of patients. Of the patients without P/LP variants, 46 patients (19%) carried a variant of unknown significance. Non-HCM P/LP variants were identified in six patients (2.5%), with two in RAF1 (p.Leu633Val, p.Ser257Leu) and one in DES (p.Arg406Trp), FHL1 (p.Glu96Ter), TTN (p.Lys23480fs), and in the mitochondrial genome (m.3243A>G). Frameshift, nonsense, and splice-variants made up 82% of all P/LP MYBPC3 variants. In all the other genes, missense mutations were the dominant form of variants. The MYBPC3 p.Gln1233Ter, the MYBPC3 p.Pro955ArgfsTer95, and the MYBPC3 p.Ser593ProfsTer11 variants were identified in 12, 7, and 13 patients, respectively. These three variants made up 36% of all patients with identified P/LP variants, raising the possibility of a possible founder effect for these mutations. Similar to other HCM populations, the MYBPC3 and the MYH7 genes seemed to be the most frequently affected genes in Hungarian HCM patients. The high prevalence of three MYBPC3 mutations raises the possibility of a founder effect in our HCM cohort.

The majority of severe COVID-19 patients develop anti-cardiac autoantibodies.

Severe cases of COVID-19 are characterized by an inflammatory burst, which is accompanied by multiorgan failure. The elderly population has higher risk for severe or fatal outcome for COVID-19. Inflammatory mediators facilitate the immune system to combat viral infection by producing antibodies against viral antigens. Several studies reported that the pro-inflammatory state and tissue damage in COVID-19 also promotes autoimmunity by autoantibody generation. We hypothesized that a subset of these autoantibodies targets cardiac antigens. Here we aimed to detect anti-cardiac autoantibodies in severe COVID-19 patients during hospitalization. For this purpose, 104 COVID-19 patients were recruited, while 40 heart failure patients with dilated cardiomyopathy and 20 patients with severe aortic stenosis served as controls. Patients were tested for anti-cardiac autoantibodies, using human heart homogenate as a bait. Follow-up samples were available in 29 COVID-19 patients. Anti-cardiac autoantibodies were detected in 68% (71 out of 104) of severe COVID-19 patients. Overall, 39% of COVID-19 patients had anti-cardiac IgG autoantibodies, while 51% had anti-cardiac autoantibodies of IgM isotype. Both IgG and IgM anti-cardiac autoantibodies were observed in 22% of cases, and multiple cardiac antigens were targeted in 38% of COVID-19 patients. These anti-cardiac autoantibodies targeted a diverse set of myocardial proteins, without apparent selectivity. As controls, heart failure patients (with dilated cardiomyopathy) had similar occurrence of IgG (45%, p = 0.57) autoantibodies, while significantly lower occurrence of IgM autoantibodies (30%, p = 0.03). Patients with advanced aortic stenosis had significantly lower number of both IgG (11%, p = 0.03) and IgM (10%, p < 0.01) type anti-cardiac autoantibodies than that in COVID-19 patients. Furthermore, we detected changes in the anti-cardiac autoantibody profile in 7 COVID-19 patients during hospital treatment. Surprisingly, the presence of these anti-cardiac autoantibodies did not affect the clinical outcome and the prevalence of the autoantibodies did not differ between the elderly (over 65 years) and the patients younger than 65 years of age. Our results demonstrate that the majority of hospitalized COVID-19 patients produce novel anti-cardiac IgM autoantibodies. COVID-19 also reactivates resident IgG autoantibodies. These autoantibodies may promote autoimmune reactions, which can complicate post-COVID recuperation, contributing to post-acute sequelae of COVID-19 (long COVID).

Hypophosphorylation of the Stiff N2B titin isoform raises cardiomyocyte resting tension in failing human myocardium.

High diastolic stiffness of failing myocardium results from interstitial fibrosis and elevated resting tension (F(passive)) of cardiomyocytes. A shift in titin isoform expression from N2BA to N2B isoform, lower overall phosphorylation of titin, and a shift in titin phosphorylation from N2B to N2BA isoform can raise F(passive) of cardiomyocytes. In left ventricular biopsies of heart failure (HF) patients, aortic stenosis (AS) patients, and controls (CON), we therefore related F(passive) of isolated cardiomyocytes to expression of titin isoforms and to phosphorylation of titin and titin isoforms. Biopsies were procured by transvascular technique (44 HF, 3 CON), perioperatively (25 AS, 4 CON), or from explanted hearts (4 HF, 8 CON). None had coronary artery disease. Isolated, permeabilized cardiomyocytes were stretched to 2.2-microm sarcomere length to measure F(passive). Expression and phosphorylation of titin isoforms were analyzed using gel electrophoresis with ProQ Diamond and SYPRO Ruby stains and reported as ratio of titin (N2BA/N2B) or of phosphorylated titin (P-N2BA/P-N2B) isoforms. F(passive) was higher in HF (6.1+/-0.4 kN/m(2)) than in CON (2.3+/-0.3 kN/m(2); P<0.01) or in AS (2.2+/-0.2 kN/m(2); P<0.001). Titin isoform expression differed between HF (N2BA/N2B=0.73+/-0.06) and CON (N2BA/N2B=0.39+/-0.05; P<0.001) and was comparable in HF and AS (N2BA/N2B=0.59+/-0.06). Overall titin phosphorylation was also comparable in HF and AS, but relative phosphorylation of the stiff N2B titin isoform was significantly lower in HF (P-N2BA/P-N2B=0.77+/-0.05) than in AS (P-N2BA/P-N2B=0.54+/-0.05; P<0.01). Relative hypophosphorylation of the stiff N2B titin isoform is a novel mechanism responsible for raised F(passive) of human HF cardiomyocytes.

Role of 3D echocardiography-determined atrial volumes in distinguishing between pre-capillary and post-capillary pulmonary hypertension.

AIMS: The current guidelines on pulmonary hypertension (PH) recommend the use of invasive examination for differentiating between left-sided heart disease-related (post-capillary) and pre-capillary PH. However, atrial sizes are considered markers of ventricular filling pressures. Therefore, we aimed to test the clinical applicability of atrial volumes measured by transthoracic three-dimensional echocardiography (3DE) in differentiating between pre-capillary and post-capillary PH. METHODS AND RESULTS: Seventy-five consecutive patients with PH were prospectively examined with transthoracic 3DE. After less than 24 h, the patients underwent right heart catheterization and 3DE and were classified as pre-capillary or post-capillary PH according to the recommendations of the ESC guidelines. The atrial volumes were measured offline with dedicated commercial software. Thirty-eight patients (13 men, age 65 ± 18 year) had pre-capillary PH, and 37 (23 men, age 62 ± year) had post-capillary PH. The mean pulmonary artery pressures were similar in patients with pre-capillary and post-capillary PH (38 [IQR 26, 54] mmHg vs. 41 [IQR 33, 48] mmHg, respectively, P = 0.49). The left atrial indexed maximum (LAVi max) and minimum (LAVi min) volumes were significantly larger in the post-capillary PH patient group than in the pre-capillary PH patient group (LAVi max: 64 ± 32 mL/m2 vs. 41 ± 25 mL/m2 , P = 0.001; LAVi min: 50 ± 22 mL/m2 vs. 26 ± 24 mL/m2 , P < 0.0001). The indexed right atrial minimum volume (RAVi min) was also higher in patients with post-capillary PH (51 ± 27 mL/m2 vs. 38 ± 26 mL/m2 ; P = 0.02). Both the left atrial (LA) and right atrial (RA) volumes, especially the LA minimum volume, correlated with the pulmonary artery wedge pressure (PAWP) (r = 0.62 (P < 0.0001) for LAV min vs. r = 0.49 (P < 0.0001) for LAV max; r = 0.32 (P = 0.005) for RAV min vs. r = 0.24 (P = 0.04) for RAV max). Multivariate logistic regression analysis showed that LAVi min was an independent predictor of post-capillary PH. In the receiver operating characteristic (ROC) curves of parameters predicting the post-capillary PH, the areas under the curve (AUC) for LAVi min, LAVi max, and RAVi min were 0.86 (95% CI, 0.76-0.95), 0.78 (95% CI, 0.67-0.89), and 0.66 (0.53-0.78), respectively. Concerning the performance of the atrial volume ratio for differentiating post-capillary PH, the AUC of the atrial volume ratio was significantly lower [AUC: 0.66 (95% CI, 0.53-0.78)]. The ROC analysis indicated a possible cutoff value of 27.7 mL/m2 for LAVi min to predict post-capillary PH (AUC = 0.86; sensitivity = 86%, specificity = 76%). CONCLUSIONS: The BSA-indexed left atrial minimum volume measured by transthoracic 3DE is a useful parameter for differentiating pre-capillary from post-capillary pulmonary hypertension.

Rationale and Design of the Efficacy of a Standardized Diuretic Protocol in Acute Heart Failure Study.

AIMS: Although acute heart failure (AHF) with volume overload is treated with loop diuretics, their dosing and type of administration are mainly based upon expert opinion. A recent position paper from the Heart Failure Association (HFA) proposed a step-wise pharmacologic diuretic strategy to increase the diuretic response and to achieve rapid decongestion. However, no study has evaluated this protocol prospectively. METHODS AND RESULTS: The Efficacy of a Standardized Diuretic Protocol in Acute Heart Failure (ENACT-HF) study is an international, multicentre, non-randomized, open-label, pragmatic study in AHF patients on chronic loop diuretic therapy, admitted to the hospital for intravenous loop diuretic therapy, aiming to enrol 500 patients. Inclusion criteria are as follows: at least one sign of volume overload (oedema, ascites, or pleural effusion), use ≥ 40 mg of furosemide or equivalent for >1 month, and a BNP > 250 ng/L or an N-terminal pro-B-type natriuretic peptide > 1000 pg/L. The study is designed in two sequential phases. During Phase 1, all centres will treat consecutive patients according to the local standard of care. In the Phase 2 of the study, all centres will implement a standardized diuretic protocol in the next cohort of consecutive patients. The protocol is based upon the recently published HFA algorithm on diuretic use and starts with intravenous administration of two times the oral home dose. It includes early assessment of diuretic response with a spot urinary sodium measurement after 2 h and urine output after 6 h. Diuretics will be tailored further based upon these measurements. The study is powered for its primary endpoint of natriuresis after 1 day and will be able to detect a 15% difference with 80% power. Secondary endpoints are natriuresis and diuresis after 2 days, change in congestion score, change in weight, in-hospital mortality, and length of hospitalization. CONCLUSIONS: The ENACT-HF study will investigate whether a step-wise diuretic approach, based upon early assessment of urinary sodium and urine output as proposed by the HFA, is feasible and able to improve decongestion in AHF with volume overload.

More severe cellular phenotype in human idiopathic dilated cardiomyopathy compared to ischemic heart disease.

Activation of the ß-adrenergic receptor (ßAR) pathway is the main mechanism of the heart to increase cardiac output via protein kinase A (PKA)-mediated phosphorylation of cellular target proteins, and perturbations therein may contribute to cardiac dysfunction in heart failure. In the present study a comprehensive analysis was made of mediators of the ßAR pathway, myofilament properties and cardiac structure in patients with idiopathic (IDCM; n = 13) and ischemic (ISHD; n = 10) cardiomyopathy in comparison to non-failing hearts (donor; n = 10) for the following parameters: ßAR density, G-coupled receptor kinases 2 and 5, stimulatory and inhibitory G-proteins, phosphorylation of myofilament targets of PKA, protein phosphatase 1, phospholamban, SERCA2a and single myocyte contractility. All parameters exhibited the expected alterations of heart failure, but for most of them the extent of alteration was greater in IDCM than in ISHD. Histological analysis also revealed higher collagen in IDCM compared to ISHD. Alterations in the ßAR pathway are more pronounced in IDCM than in ISHD and may reflect sequential changes in cellular protein composition and function. Our data indicate that cellular dysfunction is more severe in IDCM than in ISHD.

Distinct myocardial effects of beta-blocker therapy in heart failure with normal and reduced left ventricular ejection fraction.

AIMS: Left ventricular (LV) myocardial structure and function differ in heart failure (HF) with normal (N) and reduced (R) LV ejection fraction (EF). This difference could underlie an unequal outcome of trials with beta-blockers in heart failure with normal LVEF (HFNEF) and heart failure with reduced LVEF (HFREF) with mixed results observed in HFNEF and positive results in HFREF. To investigate whether beta-blockers have distinct myocardial effects in HFNEF and HFREF, myocardial structure, cardiomyocyte function, and myocardial protein composition were compared in HFNEF and HFREF patients without or with beta-blockers. METHODS AND RESULTS: Patients, free of coronary artery disease, were divided into beta-(HFNEF) (n = 16), beta+(HFNEF) (n = 16), beta-(HFREF) (n = 17), and beta+(HFREF) (n = 22) groups. Using LV endomyocardial biopsies, we assessed collagen volume fraction (CVF) and cardiomyocyte diameter (MyD) by histomorphometry, phosphorylation of myofilamentary proteins by ProQ-Diamond phosphostained 1D-gels, and expression of beta-adrenergic signalling and calcium handling proteins by western immunoblotting. Cardiomyocytes were also isolated from the biopsies to measure active force (F(active)), resting force (F(passive)), and calcium sensitivity (pCa(50)). Myocardial effects of beta-blocker therapy were either shared by HFNEF and HFREF, unique to HFNEF or unique to HFREF. Higher F(active), higher pCa(50), lower phosphorylation of troponin I and myosin-binding protein C, and lower beta(2) adrenergic receptor expression were shared. Higher F(passive), lower CVF, lower MyD, and lower expression of stimulatory G protein were unique to HFNEF and lower expression of inhibitory G protein was unique to HFREF. CONCLUSION: Myocardial effects unique to either HFNEF or HFREF could contribute to the dissimilar outcome of beta-blocker therapy in both HF phenotypes.

The peroxynitrite evoked contractile depression can be partially reversed by antioxidants in human cardiomyocytes.

In this study, we aimed to determine the contribution of peroxynitrite-dependent sulfhydryl group (SH) oxidation to the contractile dysfunction in permeabilized left ventricular human cardiomyocytes using a comparative approach with the SH-oxidant 2,2'-dithiodipyridine (DTDP). Additionally, different antioxidants: dithiothreitol (DTT), reduced glutathione (GSH) or N-acetyl-L-cysteine (NAC) were employed to test reversibility. Maximal isometric active force production (F(o)) and the maximal turnover rate of the cross-bridge cycle (k(tr,max)) illustrated cardiomyocyte mechanics. SH oxidation was monitored by a semi-quantitative Ellman's assay and by SH-specific protein biotinylation. Both peroxynitrite and DTDP diminished F(o) in a concentration-dependent manner (EC(50,peroxynitrite) = 49 microM; EC(50,DTDP) = 2.75 mM). However, k(tr,max) was decreased only by 2.5-mM DTDP, but not by 50 microM peroxynitrite. The diminution of F(o) to zero by DTDP was paralleled by the complete elimination of the free SH groups, while the peroxynitrite-induced maximal reduction in free SH groups was only to 58 +/- 6% of the control (100%). The diminutions in F(o) and free SH groups evoked by 2.5-mM DTDP were completely reverted by DTT. In contrast, DTT induced only a partial restoration in F(o) (DeltaF(o,): approximately 13%; P < 0.05) despite full reversion in protein SH content after 50 microM peroxynitrite. Although, NAC or DTT were equally effective on F(o) after peroxynitrite exposures, NAC or GSH did not restore F(o) or k(tr,max) after DTDP treatments. Our results revealed that the peroxynitrite-evoked cardiomyocyte dysfunction has a small, but significant component resulting from reversible SH oxidation, and thereby illustrated the potential benefit of antioxidants during cardiac pathologies with excess peroxynitrite production.